Round control device



Dec. 31, 1968 F. P. REED I I aouub CONTROL DEVICE Filed June 27, 19s? Sheet INVENTOR :Erefleri EkEEEEfl.

BY m ATI'O'RNEY Sheet INVENTOR FTEElEfiBkERE EEL Dec. 31, 1968 F. P. REED ROUND CONTROL DEVICE Filed June 27, 1967' Dec. 31, 1968 F. P. REED ROUND CONTROL DEVICE Sheet Filed June 27, 1967 m m Y. W 4 W w m 4 W E m N. R W m wwm A :u A E Y 1 18 United States Patent 3,418,879 ROUND CONTROL DEVICE Frederick P. Reed, Ludlow, Mass, assignor to the United States of America as represented by the Secretary of the Army Filed June 27, 1967, Ser. No. 649,363 4 Claims. (Cl. 89-33) ABSTRACT OF THE DISCLOSURE A pair of round control devices cooperate with other firearm elements in holding cartridges, fed downwardly between the devices to a feeding position, for envelopment by a reciprocating barrel. Each of the round control devices include a pair of longitudinally spaced coil springs which are contactable with the cartridge fore and aft of its center of gravity and which are deflectable by radial pressure to permit passage of the cartridge thereby, and envelopment by the barrel, but are axially incompressible after springing back to normal positions to firmly hold the feeding position cartridge for barrel envelopment.

The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

The invention relates to machine guns of the type such as is disclosed in US. Patents 3,318,191 to Reed, 3,320,- 855 to Reed et al., and 3,340,770 to Edward P. Santos.

Trouble has been experienced with such machine guns because of jamming caused by the cartridge in the feeding position being misaligned with the barrel chamber as the barrel moves rearwardly to envelop it for discharge. This misalignment results from the cartridge being held by the feed pawl and a pair of round stops solely at the area of the center of gravity. This support is not sufficient to completely secure the cartridge against teetering caused by weapon vibration during firing and therefore when the teetering is severe the front end of the cartridge contacts the rear face of the rearwardly moving barrel rather than entering the chamber, causing the machine gun to jam.

It is, therefore, the principal object of this invention to provide simple but effective means for securely holding the feeding position cartridge against teetering. Such means consist of axially incompressible but radially de fiectable coil springs which are located in pairs on opposite sides of the feed port through which the cartridges pass into the receiver. The front ones of the springs are arranged to contact the cartridge forwardly of its center of gravity with the rear ones contacting the cartridge rearwardly thereof. The springs are arranged to be radially deflected by a cartridge when passing to the feeding position and then, when the cartridge is located in the feeding position, spring back to their normal positions to cooperate with the round stops in securely holding the cartridge in coaxial alignment with the barrel.

A further advantage of this invention is that it eliminates any need to change the components of the machine gun when cartridges having cases of different material are used. A change in case material changes the center of gravity of the cartridge, sometimes considerably, and where the feeding position cartridge is supported in the area of the center of gravity this requires that the feed pawl and round stop components be changed to conform to the new location of the center of gravity.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

FIG. 1 is an elevational view of the receiver and cam drum section of a machine gun of the aforementioned type with the barrel located in its forward position;

FIG. 2 is an enlarged view taken along line 22 of FIG. 1 and shows a cartridge moved by the feed pawl towards the feeding position;

FIG. 3 is a view similar to FIG. 2 but shows the cartridge in the feeding position;

FIG. 4 is a view similar to FIG. 3 but shows the barrel in its rearward firing position;

FIG. 5 is a view taken along line 55 of FIG. 3;

FIG. 6 is a view taken along line 6-6 of FIG. 4; and

FIG. 7 is a perspective view of one of the round control units.

Shown in the figures is a machine gun 12 having a receiver 14 and a barrel 16 which reciprocates between a forward cartridge loading position and a rearward firing position. A feeding mechanism 18 includes a feed pawl 20 which is arranged for vertical reciprocation to transfer a cartridge 22 dowr wardlv from feeding mechanism 18 into receiver 14 to a feeding position in coaxial alignment with barrel 16. Receiver 14 includes a feed port 24 through which cartridge 22 is transferred into the receiver and an ejection port 26 located in the bottom of the receiver for ejection of the fired case of cartrid e 22 therethrough.

Cartridge 22 is stopped in the feeding position by a pair of round stops 40 which are fully described in the aforementioned patent to Edward A. Santos. Each of the round stops 40 is mounted in a channel 42 provided therefor in receiver 14 and such channels are symmetrically disposed apart on opposite sides of ejection port 26. A tongue '43 on each of the round stops 40 provides the point of contact between the round stop and cartridge 22 and the tongues are arranged to contact the cartridge :at approximately the area of the center of gravity thereof. Round stops 40 are each pivotally mounted between the front and rear ends thereof on a pin 44 so as to be displaceable by barrel 16 between a stopping position wherein tongues 43 are positioned to stop cartridge 22 at the feeding position and an open position wherein the tongues are clear of the barrel when adjacent its firing position, to prevent interference therewith, and of ejection port 26 to permit passage of the fired case of the cartridge therethrough.

\Vhen cartridge 22 is located in its feeding position it is held steady therein ready for en-velopment by barrel 1-6 by a pair of round control units 46 which are mounted in receiver 14 opposite round stops 40, as shown in FIG. 3, to cooperate therewith.

As is especially well shown in FIG. 7, each of the round control units 46 includes an essentially rectangular block 48 which is replaceably mounted in a longitudinal recess provided therefor inside receiver 14. Each of the blocks 48 carries a pair of extensible coil springs 52 each of which is mounted at one end therein so that its longitudinal axis coincides with a radius respective to the extended longitudinal axis AA of barrel 16. Springs 52 are longitudinally spaced in blocks 48 which are located so that the front ones of the springs are contactable by cartridge 22 forwardly of the center of gravity thereof and the rear ones of the springs are contactable by the cartridge rearwardly of the center of gravity.

Each of the springs 52 is composed of a plurality of coils 54 which are resiliently held in contact so that the spring has a cylindrical configuration which is rigidly incompressible when axial pressure is applied to the end thereof but is defiectable by radial pressure. When the radial pressure is removed each of the springs is arranged 3 to resiliently return to its normal position. Provided in the face of each of the blocks 48 from which springs 52 extend is a pair of slots 56 which are arranged to receive the extending ends of the respective ones of the springs when deflected rearwardly by barrel 16 when moving to its firing position.

Thus, when cartridge 22 is transferred by feed pawl 20 to its feeding position it passes between round control units 46 to contact the extending ends of springs 52 which are deflected downwardly thereby to permit the passage of the cartridge. With feed pawl 20 arranged to apply its pressure against cartridge 22 at the center of gravity thereof, during transfer to the feeding position, and with the front and rear pairs of springs 52 arranged to offer equal resistance to the passage of the cartridge therebetween when it is longitudinally disposed, respective to the axis of barrel 16, but unequal resistance when the cartridge deviates therefrom, the cartridge is maintained in its longitudinal position during transfer to the feeding position regardless of the attitude of machine gun 12.

When cartridge 22 is adjacent its feeding position, the ends of springs 52 slip over the case of the cartridge and thereby permit the springs to return to their normal positions, as shown in FIG. 3, for terminal contact with the cartridge. In their normal positions, springs 52 are rigid against axial compression and thereby the feeding position cartridge 22 is firmly supported underneath at the center of gravity by round stops 40 and oppositely, forwardly and rearwardly of the center of gravity, by the springs. Thus, cartridge 22 is secured against teetering and consequential misalignment with barrel 16 while being enveloped thereby.

When the projectile of cartridge 22 is located within barrel 16, the rear face thereof contacts the forward ones of the springs 52 to cause deflection thereof into their respective slots 56 and thereby clear the barrel for its continued movement to firing position. Next, round stops 40 are actuated by barrel 16 to their open positions and then as the barrel continues rearwardly the rear ones of springs 52 are contacted by the rear face of the barrel to be defiected thereby into their respective slots 56. Thus, cartridge 22 is positively held against misalignment with barrel 16 while being enveloped thereby.

When cartridge 22 is fired and barrel 16 moves forwardly springs 52 are released after the barrel passes thereby and free to resiliently return to their normal positions ready to aid in supporting the next incoming cartridge.

I claim:

1. In a machine gun having a receiver, a barrel disposed for longitudinal reciprocation between a forward cartridge loading position and a rearward firing position and a feeding mechanism including a vertically reciprocating feed pawl for transferring a cartridge through a feed port in the receiver to a feeding position therein in coaxial alignment with the barrel for envelopment thereby, the combination including a pair of round stops arranged to stop downward transfer of the cartridge by the feed pawl at the feeding position, and a pair of round control devices arranged in the receiver opposite said round stops for cooperation therewith in securing the cartridge against misalignment with the barrel during envelopment thereby, each of said round control devices including at least one extending member of the structural nature to be defiectable by the cartridge in one direction out of the way thereof during transfer to the feeding position, to rigidly hold the cartridge against said round stops when in the feeding position and to be defiectable in another direction by the barrel to prevent interference therewith during envelopment of the cartridge.

2. In a machine gun having a receiver, a barrel disposed for longitudinal reciprocation between a forward cartridge loading position and a rearward firing position and a feeding mechanism including a vertically reciprocating feed pawl for transferring a cartridge through a feed port in the receiver to a feeding position therein in coaxial alignment with the barrel for envelopment thereby, the combination including a pair of round stops arranged to stop downward transfer of the cartridge by the feed pawl at the feeding position, and a pair of round control devices arranged in the receiver opposite said round stops for cooperation therewith in securing the cartridge against misalignment with the barrel during envelopment thereby and on opposite sides of the feed port, and each of said round control devices includes a pair of resilient elements arranged for contact by the cartridge during transfer to the feeding position, said resilient elements in each of said round control devices being dis posed so as to extend into the receiver radially respective to the extended central axis of the barrel and respectively contact the cartridge forwardly and rearwardly of the center of gravity thereof.

3. The invention as defined in claim 2 wherein said resilient elements are arranged to be deflected by the cartridge during passage to the feeding position and to return to normal positions for terminal contact with the cartridge when located in the feeding position.

4. The invention as defined in claim 2 wherein each of the resilient members consists of a plurality of coils resiliently held together to form a coil spring of cylindrical configuration which is incompressible by an axial force applied against the end thereof but is defiectable by application of a radial force.

References Cited UNITED STATES PATENTS 908,521 1/1909 Trundle 89-161 2,192,677 3/ 1940 Hoagland et al. 3,311,021 3/1967 Reed 89-33 3,340,770 9/1967 Santos 8933 BENJAMIN A. BORCHBLT, Primary Examiner.

S. C. BEATLE, Assistant Examiner. 

